Manchester United forward Jesse Lingard will now be represented by super-agent Mino Raiola.
Raiola's clients include Lingard's team-mate Paul Pogba and former United players Zlatan Ibrahimovic and Henrikh Mkhitaryan.
Raiola has previously criticised United and the club's relationship with Pogba, who admitted in June that he was considering leaving Old Trafford for a "new challenge".
In a recent interview in Italy, Raiola labelled United a "club out of touch with reality" and said he would not send any of his other clients to Old Trafford as they would "ruin Maradona, Pele and Maldini".
However, Raiola has since told Sky Sports News that Pogba is happy at United and will stay at the club - as long as they fight for trophies.
His comments prompted a strong response from United manager Ole Gunnar Solskjaer.
When asked if agents should speak about clubs ahead of Saturday's FA Cup third-round tie against Wolves, Solskjaer said: "No.
"I can speak to Paul about it. I don't think I should talk to - or about - agents that talk about us.
"But Paul is our player and agents are hired by players - not the opposite way around. It is not agents' players, it is our players."
Ole: Lingard has toned down social media
Lingard signed a four-year deal with United in 2017 which is due to expire at the end of next season, unless the club trigger an option for a further year.
The 27-year-old has scored just once this season but played a key role in last month's wins over Tottenham and Manchester City.
Lingard missed the draw with Wolves through illness but Solskjaer hopes to have him back before they face Manchester City in first leg of their Carabao Cup semi-final on Tuesday, live on Sky Sports.
"Jesse has had ups and downs as I've spoken about before. The games against City and Spurs, they're two examples of how important he can be for us in different games," said Solskjaer.
"Of course we want him back, scoring goals, making assists. There's no one who runs as much as Jesse. He's great in pressing, he's a lively, bubbly character."
Solskjaer believes Lingard has toned down his use of social media, and admits he speaks to his players about how they portray themselves online.
"You don't see as much in the social media as you used to with Jesse, he's got his head down and working hard," said Solskjaer. "I've known him for many years, he's getting back to the Jesse I knew."
He added: "I think it's part of being a Man United player - how you come across. I think it's important that you do give of yourself, but in a positive way and it's more football related."
'United frustrated at Lingard teaming up with Raiola'
Sky Sports News reporter James Cooper writes...
I'm sure the news that Lingard has been added to Mino Raiola's stable hasn't gone down well behind closed doors at Old Trafford.
The ongoing skirmishes regarding Pogba, who's just undergone another operation, and missing out on Erling Haaland mean Raiola probably isn't Manchester United's favourite agent. Add his recent remarks to that assessment and you can understand the club's frustration that Lingard has made this decision.
However, from a player's point of view you can understand it too. Raiola gets results for his players, whether that's big money or big moves or even both.
Lingard told me before Christmas that he'd rediscovered the "real Jesse Lingard" and his performances in the victories over Spurs and Manchester City were encouraging, since then he's struggled to find the same sort of form.
Linking up with Raiola will only further ignite the speculation as to what the future may hold for a player who's hoping the end of the season will see him as part of England's squad for the European Championships.